Results 151 to 160 of about 112,509 (371)

Sulfide–Metal Assemblages on CR2 Chondrule Rims: Products of Nebular Fission–Sulfidization and Parent Body Oxidation–Serpentinization

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract We conducted a scanning electron microscopy (SEM) and transmission electron microscopy (TEM) study of sulfide–metal assemblages (SMAs) in minimally to moderately altered CR2 chondrites. The assemblages occur on chondrule rims and consist of kamacite cores rimmed by pyrrhotite.
S. A. Singerling, A. J. Brearley
wiley   +1 more source

Experimental constraints on the origin of metal and carbon in ureilite meteorites

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Ureilites are carbon‐rich ultramafic achondrites that display unique textures, including strips of metal and carbon phases situated along grain boundaries and in fractures. Shock metamorphism observed in ureilites suggests an episode of brittle deformation caused by impact disruption of their parent body.
Nicolas P. Walte   +2 more
wiley   +1 more source

Radiation characteristics of coals at different stages of metamorphism

open access: yesЗаписки Горного института
The formation of deposits and subsequent metamorphic processes that affect concentrations of radioactive elements in coal can indicate ongoing geological activities, therefore, analyzing trends in the radiation characteristics of coal throughout the ...
Nadezhda L. Aluker   +2 more
doaj  

Chromite in main group pallasite meteorites: Accessory mineral tracing planetesimal differentiation

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Main group pallasite meteorites (PMG) are samples of an early, highly differentiated magmatic planetesimal dominated by olivine and metal‐sulfide‐phosphide assemblages with accessory chromite among other phases. This mineralogy reflects mantle‐ and core‐related reservoirs, but the relative contributions of each and the overall petrogenesis are
Seann J. McKibbin   +6 more
wiley   +1 more source

Neoproterozoic ultramafic and mafic magmatism in the Eastern Cordillera of the central peruvian Andes: the Tapo Massif [PDF]

open access: yes, 2010
A highly dismembered assemblage of ultramafic and mafic rocks is exposed in the Eastern Cordillera of the Central Peruvian Andes, extending along a discontinuous NW-SE belt over some 250 km between 12° and 9° S of latitude.
Acosta, Jorge   +4 more
core   +2 more sources

Aligned hydrothermal fluid‐flow pathways in Middle Permian near‐shore marine sediments beneath a basaltic lava flow

open access: yesSedimentology, EarlyView.
ABSTRACT Tubular and curviplanar structures, outlined by the occurrence of haematite/goethite, chlorite, quartz and albite, are developed in the Middle Permian Broughton Formation in the southern Sydney Basin, New South Wales, Australia. These structures are interpreted as fluid‐flow pathways resulting from the ejection of heated pore fluids as a thick
Paul F. Carr   +5 more
wiley   +1 more source

Origin of the ungrouped achondrite NWA 4518: mineralogy and geochemistry of FeNi-metal [PDF]

open access: yes, 2011
Ungrouped achondrite NWA 4518 is an ultramafic breccia with abundant siderophile rich IIA-like metal. Its silicate chemistry is similar to that of WINs, HEDs, and silicate inclusions of IIE irons.
Franchi, I.   +5 more
core  

Home - About - Disclaimer - Privacy